Abstract
Calder and Young (2005) have suggested that the greater role of posterior superior temporal sulcus (pSTS) in coding changeable (e.g., facial expression, eye gaze) versus static (e.g., identity) facial features may reflect the wider role of this region in processing social signals from multiple modalities. Indeed, previous research has shown that pSTS responds to emotional expression cues in the visual and auditory modalities (e.g., Hagan et al., 2010). Recent work (Stoyanova et al., in press) indicates that discrimination of direct gaze may be influenced by an accompanying, ostensive auditory signal with similar value (i.e., hearing one's own name). However, it is unclear whether the natural co-occurrence of these visual and auditory ostensive signals is reflected in a common neutral substrate in pSTS. To address this question, we employed a 2 × 2 factorial design with the factors of gaze direction (DIRECT/AVERTED) and name (OWN/OTHER). In a rapid event-related functional MRI study, participants viewed video clips of actors engaging in direct or averted gaze while calling out participants' own name or one of three other, syllable-matched, first names. Participants were asked to judge whether the person in the video was looking at or away from them. Face selective regions in the STS were localized in a separate functional localizer scan. Whole-brain random effects analyses revealed extensive bilateral activation in STS/STG for OWN>OTHER NAME as well as a more focussed effect of DIRECT>AVERTED GAZE in right posterior STS. In line with our hypothesis, a conjunction analysis confirmed that hearing one's own name, relative to another, and viewing direct, versus averted, gaze, engages the same region of right pSTS. Our results suggest that the role of pSTS in coding gaze direction may reflect a wider role in processing ostensive cues in different modalities.